"So Challenging" is slang for "really" or "uncontrollable." When Chloe states "Wow, my accent is returning so tricky right this moment," she implies that her southern accent is coming back devoid of her able to manage it. The phrase 'the strongest' is appropriate, when 'the most strong' is incorrect. In https://vapeandchews.com/product/strongest-cbd-disposable-vape-uk/